Arrangement and devices configured for carrying out optical absorption spectroscopy

Abstract

An implantable fluorescent concentrator is configured to be inserted in vivo as a subcutaneous light source for optical absorption spectroscopy of surface-near tissue layers. As a result, certain and reliable results of the optical absorption spectroscopy are achievable. Furthermore, various analytes with different absorption properties are certainly and reliably quantifiable.

What is claimed is: 
     
       1. A device configured to be inserted into tissue under a skin surface, comprising:
 a substrate including a material having a higher refractive index than the tissue; 
 a fluorescent material supported by the substrate, the fluorescent material configured to absorb light that is emitted onto the skin surface and further configured to convert the absorbed light into fluorescent light and emit the fluorescent light into the substrate such that the fluorescent light is totally internally reflected within the substrate when the device is in the tissue; and 
 a fluorescent-light-emitting region supported by the substrate configured to collect the totally internally reflected fluorescent light and further configured to emit the collected fluorescent light in a direction of the skin surface to leave the tissue. 
 
     
     
       2. The device according to  claim 1 ,
 wherein the fluorescent material is formed on the substrate of the device. 
 
     
     
       3. The device according to  claim 1 , wherein the fluorescent-light-emitting region is smaller than a side of the device configured to face the skin surface. 
     
     
       4. The device according to  claim 1 , wherein:
 the fluorescent-light-emitting region is one of a roughened region and a region covered with scattering particles, and 
 the device further comprises a reflector at a side of the fluorescent-light-emitting region configured to face away from the skin surface. 
 
     
     
       5. The device according to  claim 1 , further comprising at least one mirror arranged at least at one front end of the device, the at least one mirror configured to reflect into the device light rays of the fluorescent light which radiate into the device and against the front end of the device. 
     
     
       6. The device according to  claim 1 , further comprising:
 a fluorescent-light-controlling layer on a side of the device configured to face the skin surface, 
 wherein the fluorescent-light-controlling layer is formed above the fluorescent material, 
 wherein the fluorescent-light-controlling layer is substantially transparent for the light emitted onto the skin surface, 
 wherein the fluorescent-light-controlling layer is substantially reflective or absorbing for the fluorescent light, and 
 wherein the fluorescent-light-controlling layer is configured to direct the emission of the collected fluorescent light to a specific position on the skin surface. 
 
     
     
       7. The device according to  claim 6 , wherein the fluorescent-light-controlling layer is open with respect to the fluorescent-light-emitting region such that the fluorescent light emitted by the fluorescent-light-emitting region is emitted to a specific position on the skin surface. 
     
     
       8. The device according to  claim 1 , further comprising an element configured to align the device, the element further configured to enable the device to be aligned noninvasively under the skin surface. 
     
     
       9. The device according to  claim 1 , wherein the fluorescent material includes a fluorescent dye. 
     
     
       10. The device according to  claim 1 , wherein the fluorescent material includes the material of the substrate and a fluorescent dye. 
     
     
       11. The device according to  claim 1 , wherein:
 the fluorescent-light-emitting region is a surface of the substrate that extends with the skin surface, and 
 the fluorescent-light-emitting region is one of a roughened region and a region covered with scattering particles. 
 
     
     
       12. The device according to  claim 1 , wherein the fluorescent-light-emitting region is a light-scattering region in a volume of the substrate. 
     
     
       13. An arrangement, comprising:
 a device configured to be inserted into tissue under a skin surface, the device including:
 a substrate including a material having a higher refractive index than the tissue; 
 a fluorescent material supported by the substrate, the fluorescent material configured to absorb light that is emitted onto the skin surface and further configured to convert the absorbed light into fluorescent light and emit the fluorescent light into the substrate such that the fluorescent light is totally internally reflected within the substrate when the device is in the tissue; and 
 a fluorescent-light-emitting region supported by the substrate configured to collect the totally internally reflected fluorescent light and further configured to emit the collected fluorescent light in a direction of the skin surface; and 
 
 a light-detecting device configured to emit light onto the skin surface and further configured to detect and receive the fluorescent light emitted by the device. 
 
     
     
       14. The arrangement according to  claim 13 , wherein the light-detecting device includes a filter element configured to transmit the fluorescent light for evaluation in the light-detecting device and further configured to block other light emitted by the skin surface. 
     
     
       15. The arrangement according to  claim 13 , further comprising an aligning element configured to noninvasively align the device under the skin surface such that a side of the light-detecting device which is configured to emit the light and to receive the fluorescent light is substantially above a side of the device which absorbs the light and emits the fluorescent light.